Pre-Columbian ballcourts have been found throughout Mesoamerica, as for example at Copán, as far south as modern Nicaragua, and possibly as far north as what is now the U.S. The sport was also played casually for recreation by children and may have been played by women as well. Late in the history of the game, some cultures occasionally seem to have combined competitions with religious human sacrifice. The Mesoamerican ballgame had important ritual aspects, and major formal ballgames were held as ritual events. The ball was made of solid rubber and weighed as much as 4 kg (9 lbs), and sizes differed greatly over time or according to the version played. In the most common theory of the game, the players struck the ball with their hips, although some versions allowed the use of forearms, rackets, bats, butts, or handstones. The stone ballcourt goals are a late addition to the game. The rules of the Mesoamerican ballgame are not known, but judging from its descendant, ulama, they were probably similar to racquetball, where the aim is to keep the ball in play. The sport had different versions in different places during the millennia, and a newer, more modern version of the game, ulama, is still played by the indigenous populations in some places. The Mesoamerican ballgame ( Nahuatl languages: ōllamalīztli, Nahuatl pronunciation:, Mayan languages: pitz) was a sport with ritual associations played since at least 1650 BC by the pre-Columbian people of Ancient Mesoamerica. The ball in front of the goal during a game of pok-ta-pok.